Luminaire with Luminaire Module

ABSTRACT

The present technology relates to luminaires including a housing and a luminaire module disposed within the housing, where the housing has apertures through which light that is output by the luminaire module exits the luminaire towards one or more target areas.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit under 35 U.S.C. §119(e)(1) to U.S.Provisional Application No. 61/878,764, filed on Sep. 17, 2013, theentire contents of which is incorporated by reference herein.

TECHNICAL FIELD

Technologies related to solid-state luminaires and in particular tolighting devices that are configured as a luminaire with a luminairemodule are described herein.

BACKGROUND

Conventional lighting systems in the lighting field commonly harnessfairly spatially homogeneous sources within optical systems. The lightsources are often fairly bright (source luminance), and the conventionallighting systems are often provided with a single reflector system tocollect the light flux and direct it in a semi-controlled fashion, orvia secondary reflector/diffuser systems, towards a target area.Conventional lighting systems often retain a Lambertiandiffuser/reflective surface in the system such that a direct view of theLambertian source is retained in at least one field of view. This givesrise, at certain angles, to glare with the problem increasing in timewith ever brighter Light Emitting Diode (LED) sources.

SUMMARY

The present technology relates generally to solid-state luminaires andin particular to lighting devices that are configured as a luminairewith a luminaire module.

A variety of luminaires are disclosed that are configured to manipulatelight provided by one or more light-emitting elements (LEEs). Thecomponents of the luminaire can be configured in a variety of ways so avariety of intensity distributions can be output by the luminaire. Suchluminaires can be configured to provide light for particular lightingapplications, including office lighting, task lighting, cabinetlighting, garage lighting, wall wash, stack lighting, and down-lighting.

Various aspects of the invention are summarized as follows.

In general, in a first aspect, the invention features a luminaireincluding a housing having a first face with a first aperture; one ormore luminaire modules arranged within the housing, where each moduleincludes one or more light-emitting elements (LEEs) disposed on one ormore substrates and adapted to emit light in a first direction; a lightguide including an input end and an output end, and side surfacesextending from the input end to the output end, the side surfaces beingshaped to guide light emitted by the one or more LEEs and received atthe input end of the light guide in the first direction to the outputend of the light guide and provide guided light at the output end of thelight guide; and an optical extractor optically coupled with the outputend of the light guide and adapted to receive the guided light, theoptical extractor having a first redirecting surface and a first outputsurface, the first redirecting surface of the optical extractor beingadapted to reflect at least a portion of the guided light received atthe optical extractor towards the first output surface and outputredirected light from the first output surface of the optical extractorin a second direction opposing the first direction, where light outputby the optical extractor through the first output surface in the seconddirection passes through the first aperture into an ambient environmentas first light output by the luminaire.

The foregoing and other embodiments can each optionally include one ormore of the following features, alone or in combination. In someimplementations, the one or more substrates can be coupled with thefirst face of the housing. In some implementations, the opticalextractor can include a second redirecting surface and a second outputsurface on an opposite side of an optical axis of the light guiderelative to the first output surface, the second redirecting surface ofthe optical extractor can be adapted to reflect at least a portion ofthe light received at the optical extractor towards the second outputsurface and output redirected light from the second output surface ofthe optical extractor in the second direction, and the first face canhave a second aperture where light output by the optical extractorthrough the second output surface in the second direction can passthrough the second aperture into the ambient environment as second lightoutput by the luminaire.

In some implementations, the housing can include a second face opposingthe first face, such that the optical extractor is adjacent to thesecond face. In some implementations, the housing can include one ormore side faces extending from the first face along the first direction.In some implementations, the luminaire can further include a firstreflector having a first reflective surface, where the first reflectivesurface can be configured to reflect at least a portion of light that isoutput from the first output surface of the optical extractor towardsthe first aperture in the second direction as reflected light. In someimplementations, the first reflector can include a second reflectivesurface opposing the first reflective surface.

In some implementations, the housing can be recessed in a ceiling suchthat the first face of the housing is parallel to the ceiling. In someimplementations, the first face can be within a plane of the ceiling. Insome implementations, the luminaire can further include a secondreflector having a third reflective surface, where the third reflectivesurface can be configured to reflect at least a portion of light that isoutput from the second output surface of the optical extractor towardsthe second aperture in the second direction as reflected light. In someimplementations, the second reflector can include a fourth reflectivesurface opposing the third reflective surface.

In some implementations, the luminaire can further include an opticalelement disposed in at least a portion of at least one of the first orsecond aperture. In some implementations, the optical element can beconfigured to diffuse light. In some implementations, the luminaire canfurther include an optical element disposed in at least a portion of atleast one of the first or second aperture, where the optical element canbe configured to refract light. In some implementations, at least aportion of at least one of the first or second reflective surface can bespecular reflective. In some implementations, the light guide and atleast one of the first or second reflectors can be configured to mix thelight emitted by the one or more LEEs to provide a substantially uniformoutput light at the first aperture or at the first and second apertures.

In some implementations, the output light can have an isotropic colordistribution. In some implementations, the output light can have auniform intensity distribution along a direction parallel to the planarside surfaces of the light guide. In some implementations, the lightguide can include a solid transparent material and the side surfaces canbe configured to guide light via TIR. In some implementations, the lightguide can be hollow and the side surfaces can be reflectors configuredto guide light via specular reflection. In some implementations, theluminaire can further include one or more couplers positioned to receivea portion of the light emitted by corresponding one or more LEEs and canbe adapted to at least partially collimate the received portion of thelight, where the one or more couplers can be positioned to providecollimated light to the input end of the light guide.

The details of one or more implementations of the technologies describedherein are set forth in the accompanying drawings and the descriptionbelow. Other features, aspects, and advantages of the disclosedtechnologies will become apparent from the description, the drawings,and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic diagram of an example luminaire with a luminairemodule disposed within a housing.

FIG. 1B is a polar plot of an intensity profile of an example luminairehaving a housing with one light output aperture, or, optionally, a pairof light output apertures.

FIG. 2A is a perspective view of an example of an elongated luminairemodule (oriented upside down compared to FIG. 1A) with a light guide anda bidirectional optical extractor.

FIG. 2B is a perspective view of an example of an elongated light guideluminaire module with a unidirectional optical extractor.

FIG. 2C is perspective view of another example of an elongated luminairemodule with a light guide and an optical extractor.

FIG. 2D is a perspective view of an example of a rotationally symmetriclight guide luminaire module.

FIGS. 2E-2F are views of an example of an elongated luminaire modulewith curved light guide and bidirectional optical extractor.

FIGS. 3A-3C show examples of luminaires including a housing encompassingone or more luminaire modules.

Reference numbers and designations in the various drawings indicateexemplary aspects of implementations of particular features of thepresent disclosure.

DETAILED DESCRIPTION

The technologies described herein provide luminaires that can provideareas of illumination and respective intensity vectors within anilluminated environment to create a desired illumination distribution.Light that is emitted by light-emitting elements (LEEs) can be harnessedand create a virtual light source with properties that can result incompact luminaires with a small physical footprint relative to theilluminated environment.

(i) Luminaire with a Luminaire Module

FIG. 1A is a schematic diagram of an example luminaire 100 including aluminaire module 102 disposed within a housing 160. A Cartesiancoordinate system is shown in FIG. 1A for reference. The housing 160 canbe disposed in an in-ceiling or in-wall recessed enclosure to form arecessed fixture. The housing 160 includes a surface 161 with a lightoutput aperture 162′. The luminaire module 102 is disposed inside thehousing 160 and adequately mechanically held in place, for example, itmay be connected to the surface 161 of the housing 160. The light outputaperture 162′ of housing 160 faces target area I and is configured suchthat light output by the luminaire module 102 can pass through the lightoutput aperture 162′ toward the target area I. Optionally, the surface161 of the housing 160 can include another light output aperture 162″facing target area II. The other light output aperture 162″ isconfigured such that light output by the luminaire module 102 can passthrough it toward the target area II. Here, light output apertures 162′and 162″ are on opposite sides of the optical axis of the luminairemodule 102. The luminaire 100 can extend in one or more directionsperpendicular to the z-axis, have axial symmetry about different axis orhave other geometrical extensions as further described.

Luminaire module 102 includes LEEs 112 that are disposed on a substrate110. The luminaire module 102 also includes light guide 130, and opticalextractor 140.

The substrate 110 can provide any combination of thermal, structural, orelectrical functions for the LEEs 112. LEEs 112 emit light in an angularrange 115. As used herein, providing light in an “angular range” refersto providing light that propagates in one or more prevalent directionsin which each has a divergence with respect to the correspondingprevalent direction. In this context, the term “prevalent direction ofpropagation” refers to a direction along which a portion of an intensitydistribution of the propagating light has a maximum, a mean, a median orother defined direction, for example. For example, the prevalentdirection of propagation associated with the angular range can be anorientation of a lobe of the intensity distribution. (See, e.g., FIG.1B.) Also in this context, the term “divergence” refers to a solid angleoutside of which the intensity distribution of the propagating lightdrops below a predefined fraction of a maximum of the intensitydistribution. For example, the divergence associated with the angularrange can be the width of the lobe of the intensity distribution. Thepredefined fraction can be 10%, 5%, 1%, or other values, depending onthe lighting application.

Here, the light guide 130 includes side surfaces that extend from alight input surface 131 to a light output surface 132. The light guide130 is arranged to receive the light emitted by LEEs 112 in angularrange 115 at the light input surface 131 of the light guide 130. Thereceived light reflects off the side surfaces of the light guide 130 andmixes within the light guide 130. The mixing can improve luminanceand/or color uniformity at the light exit surface 132 of the light guide130 compared to the light input surface 131. Depth D of the light guide130 can be selected to achieve adequate uniformity at the light exitsurface 132 of the light guide 130. The mixed light is output throughthe light exit surface 132 with angular range 135 and received byoptical extractor 140 that is optically coupled with the light guide130.

The optical extractor 140 includes redirecting surface(s) that redirectthe light received at the optical extractor 140 towards one or morelight output surfaces of the optical extractor 140. The opticalextractor 140 outputs the redirected light through the one or more lightoutput surfaces in angular range 145′, and optionally in angular range145″. The angular ranges 145′, 145″ can be symmetric or asymmetric andcan be modified to have wider or narrower light distributions and peakintensity directions. Light in angular range 145′ is directed towardsthe light output aperture 162′. In some implementations, some or alllight within angular range 145′ can directly propagate to the lightoutput aperture 162′. In this manner, light output by the luminairemodule 102 exits the luminaire 100 through light output aperture 162′towards target area I with an angular range 165′. In implementations,where the optical extractor 140 outputs light in angular range 145″,light in angular range 145″ is directly or indirectly directed towardsthe light output aperture 162″ in the surface 161 of housing 160. Insuch implementations, light output by the luminaire module 102 can alsoexit the luminaire 100 through light output aperture 162″ towards targetarea II with an angular range 165″.

In some implementations, luminaire 100 includes a reflector 150′. Insome implementations, in addition to the reflector 150′, the luminaire100 includes another reflector 150″. Reflectors 150′, 150″ are disposedwithin the housing 160 and arranged to redirect at least a portion ofthe light that is output by optical extractor 140, towards light outputapertures 162′, 162″. For example, reflector 150′ can be arranged toredirect light that is output by the optical extractor 140 in angularrange 145′ towards the light output aperture 162′ with an angular range155′. Reflector 150″ can be arranged to redirect light that is output bythe optical extractor 140 in angular range 145″ towards the light outputaperture 162″ with an angular range 155″. Light received at light outputapertures 162′, 162″ can pass through light output apertures 162′, 162″within angular range 165′ towards target area I and within angular range165″ towards target area II, respectively.

In some implementations, the luminaire module 102 can include one ormore optical couplers 120 that are coupled with corresponding LEEs 112.In such implementations, optical couplers 120 receive light emitted bycorresponding LEEs 112 in angular range 115. The optical coupler(s) 120include one or more solid pieces of transparent material (e.g., glass ora transparent organic plastic, such as polycarbonate or acrylic) havingsurfaces that are positioned to reflect the received light in theangular range 115 and output light with an angular range 125. In someimplementations, the surfaces of the optical coupler(s) 120 are shapedto collect and collimate the received light. The optical couplers 120are optically coupled with the light input surface 131 of the lightguide 130, which receives the light that is output by optical couplers120.

In elongate implementations, light output apertures 162′, 162″ canextend along the y-axis over a fraction or the entire length of thesurface 161 of the housing 160 panel in the y-direction to allow lightto exit from the housing 160 substantially unobstructed. The lightoutput apertures 162′, 162″ can be openings or can be covered with alight-transmissive window (e.g., glass or plastic). Light-transmissivewindows can stop dust, debris, etc. from entering the housing 160 andprevent contaminating the optical components of the luminaire 100 orother system components, for example. The light-transmissive materialcan be refractively or diffusely transmitting. In the latter case, thelight intensity is homogenized along the length of the aperture.

FIG. 1B shows, for the x-z plane, a light intensity profile 101 of anexample luminaire 100. The intensity profile 101 includes lobe 165 aand, optionally, lobe 165 b. In this example, lobe 165 a corresponds tolight that is output by the luminaire 100 in angular range 165′ towardstarget area I. Lobe 165 b corresponds to light that is output byluminaire 100 in angular range 165″ towards target area II.

Here, the luminaire is configured to direct substantially all of thelight represented by lobes 165 a, 165 b that is output by luminaire 100in a range of polar angles between −10° and −30°, and +10° and +30°,respectively.

(ii) Luminaire Module

Referring to FIG. 2A, in which a Cartesian coordinate system is shownfor reference, an embodiment of a luminaire module 200 includes asubstrate 210 having a plurality of LEEs 212 distributed along thesubstrate 210. The LEEs 212 are disposed at an upper edge 231 of a lightguide 230. As shorthand, the positive z-direction is referred to hereinas the “forward” direction and the negative z-direction is the“backward” direction. Sections through the luminaire parallel to the x-zplane are referred to as the “cross-section” or “cross-sectional plane”of the luminaire module. Also, luminaire module 200 extends along they-direction, so this direction is referred to as the “longitudinal”direction of the luminaire module. Lastly, embodiments of luminairemodules can have a plane of symmetry parallel to the y-z plane, becurved or otherwise shaped. Depending on the embodiment, one or morecomponents of the luminaire module can be invariant or variant undertranslation along the y-axis. This is referred to as the “symmetryplane” of the luminaire module.

Multiple LEEs 212 are disposed on the substrate 210, although only oneof the multiple LEEs 212 is shown in FIG. 2A. For example, the pluralityof LEEs 212 can include multiple white LEDs. An optical extractor 240 isdisposed at lower edge of light guide 232. The LEEs 212 are coupled withone or more optical couplers 220 (only one of which is shown in FIG.2A).

Substrate 210, light guide 230, and optical extractor 240 extend alength L along the y-direction. Generally, L can vary as desired.Typically, L is in a range from about 1 cm to about 200 cm (e.g., 20 cmor more, 30 cm or more, 40 cm or more, 50 cm or more, 60 cm or more, 70cm or more, 80 cm or more, 100 cm or more, 125 cm or more, 150 cm ormore).

The number of LEEs 212 on the substrate 210 will generally depend, interalia, on the length L, where more LEEs are used for longer luminaires.In some embodiments, the plurality of LEEs 212 can include between 10and 1,000 LEEs (e.g., about 50 LEEs, about 100 LEEs, about 200 LEEs,about 500 LEEs). Generally, the density of LEEs (e.g., number of LEEsper unit length) will also depend on the nominal power of the LEEs andluminance desired from the luminaire module. For example, a relativelyhigh density of LEEs can be used in applications where high luminance isdesired or where low power LEEs are used. In some embodiments, theluminaire module has an LEE density along its length of 0.1 LEE percentimeter or more (e.g., 0.2 per centimeter or more, 0.5 per centimeteror more, 1 per centimeter or more, 2 per centimeter or more). Thedensity of LEEs may also be based on a desired amount of mixing of lightemitted by the multiple LEEs. In embodiments, LEEs can be evenly spacedalong the length, L, of the luminaire. In some implementations, aheat-sink 205 can be attached to the substrate 210 to extract heatemitted by the plurality of LEEs 212. The heat-sink 205 can be disposedon a surface of the substrate 210 opposing the side of the substrate 210on which the LEEs 212 are disposed.

Optical coupler 220 includes one or more solid pieces of transparentmaterial (e.g., transparent glass or plastic, such as polycarbonate oracrylic) having surfaces 221 and 222 positioned to reflect light fromthe LEEs 212 towards light guide 230. In general, surfaces 221 and 222are shaped to collect and collimate light emitted from the LEEs. In thex-z cross-sectional plane, surfaces 221 and 222 can be straight orcurved. Examples of curved surfaces include surfaces having a constantradius of curvature, parabolic or hyperbolic shapes. In someembodiments, surfaces 221 and 222 are coated with a highly reflectivematerial (e.g., a reflective metal, such as aluminum), to provide ahighly reflective optical interface. The cross-sectional profile ofoptical coupler 220 can be uniform along the length L of luminairemodule 200. Alternatively, the cross-sectional profile can vary. Forexample, surfaces 221 and/or 222 can be curved out of the x-z plane.

The exit aperture of the optical coupler 220 and the adjacent upper edgeof light guide 231 are optically coupled. For example, the surfaces of asolid optical coupler and a solid light guide can be attached using amaterial that substantially matches the refractive index of the materialforming the optical coupler 220 or light guide 230 or both. The opticalcoupler 220 can be affixed to light guide 230 using an index matchingfluid, grease, or adhesive. In some embodiments, optical coupler 220 isfused to light guide 230 or they are integrally formed from a singlepiece of material.

Light guide 230 is formed from a piece of transparent material (e.g.,glass or a transparent plastic, such as polycarbonate or acrylic) thatcan be the same or different from the material forming optical couplers220. Light guide 230 extends length L in the y-direction, has athickness uniform T in the x-direction, and a uniform depth D in thez-direction. The dimensions D and T are generally selected based on thedesired optical properties of the light guide. During operation, lightcoupled into the light guide from optical coupler 220 (depicted byangular range 225) reflects off the planar surfaces of the light guideby TIR and mixes within the light guide. The mixing can help achieveilluminance and/or color uniformity at the distal portion of the lightguide 232 at optical extractor 240. The depth, D, of light guide 230 canbe selected to achieve adequate uniformity at the exit aperture (i.e.,at end 232) of the light guide. In some embodiments, D is in a rangefrom about 1 cm to about 20 cm (e.g., 2 cm or more, 4 cm or more, 6 cmor more, 8 cm or more, 10 cm or more, 12 cm or more).

In some implementations, the surfaces of the light guide can includeoptical structures (e.g., scattering centers) or surface imperfectionsthat can cause light to escape through the surface of the light guide,for example, to create a soft glow.

In general, optical couplers 220 are designed to restrict the angularrange of light entering the light guide 230 (e.g., to within +/−40degrees) so that at least a substantial amount of the light is coupledinto spatial modes in the light guide 230 that undergoes TIR at theplanar surfaces. In the illustrated example, light guide 230 has auniform thickness T, which is the distance separating two planaropposing surfaces of the light guide. Generally, T is sufficiently largeso the light guide has an aperture at upper surface 231 sufficientlylarge to approximately match (or exceed) the exit aperture of opticalcoupler 220. In some embodiments, T is in a range from about 0.05 cm toabout 2 cm (e.g., about 0.1 cm or more, about 0.2 cm or more, about 0.5cm or more, about 0.8 cm or more, about 1 cm or more, about 1.5 cm ormore). Depending on the embodiment, the narrower the light guide thebetter it may mix light. A narrow light guide also provides a narrowexit aperture. As such light emitted from the light guide can beconsidered to resemble the light emitted from a one-dimensional linearlight source, also referred to as an elongate virtual filament.

As discussed previously, length L corresponds to the length of theluminaire and can vary as desired.

While optical coupler 220 and light guide 230 are formed from solidpieces of transparent material, hollow structures are also possible. Forexample, the optical coupler 220 or the light guide 230 or both may behollow with reflective inner surfaces rather than being solid. As suchmaterial cost can be reduced and absorption in the light guide can bemitigated. A number of specular reflective materials may be suitable forthis purpose including materials such as 3M Vikuiti™ or Miro IV™ sheetfrom Alanod Corporation where greater than 90% of the incident light canbe efficiently guided to the optical extractor.

Optical extractor 240 is also composed of a solid piece of transparentmaterial (e.g., glass or a transparent plastic, such as polycarbonate oracrylic) that can be the same as or different from the material forminglight guide 230. The optical extractor 240 includes surfaces 242 and 244and curved surfaces 246 and 248. The surfaces 242 and 244 representfirst and second portions of a redirecting surface 243, while the curvedsurfaces 246 and 248 represent first and second output surfaces of theluminaire module 200.

Surfaces 242 and 244 of luminaire module 200 can be flat and coated witha reflective material (e.g., a highly reflective metal, such as aluminumor silver) over which a protective coating may be disposed. Furthermore,a material with reflectivity properties that can be controlled duringoperation, for example an electrochromic, electrowetting, liquid crystalor other mirror layer, may be employed. Thus, surfaces 242 and 244provide a highly reflective optical interface for light entering aninput end 232′ of the optical extractor 240 from light guide 230.

In the x-z cross-sectional plane, the lines corresponding to surfaces242 and 244 have the same length and form a v-shape that meets at avertex 241. In general, the included angle of the v-shape can vary asdesired. For example, in some embodiments, the included angle can berelatively small (e.g., from 30° to 60°). In some embodiments, theincluded angle is in a range from 60° to 120° (e.g., about 90°). Theincluded angle can also be relatively large (e.g., in a range from 120°to 150° or more). In the example implementation shown in FIG. 2A, theoutput surfaces 246 and 248 of the optical extractor 240 are curved witha constant radius of curvature that is the same for both. Accordingly,luminaire module 200 has a plane of symmetry intersecting vertex 241parallel to the y-z plane.

The surface of optical extractor 240 adjacent to the lower edge 232 oflight guide 230 is optically coupled to edge 232. For example, opticalextractor 240 can be affixed to light guide 230 using an index matchingfluid, grease, or adhesive. In some embodiments, optical extractor 240is fused to light guide 230 or they are integrally formed from a singlepiece of material.

During operation, light exiting light guide 230 through end 232 impingeson the reflective interfaces at portions of the redirecting surface 242and 244 and is reflected outwardly towards output surfaces 246 and 248,respectively, away from the symmetry plane of the luminaire. The firstportion of the redirecting surface 242 provides light having an angulardistribution 238 towards the output surface 246, the second portion ofthe redirecting surface 244 provides light having an angulardistribution 238′ towards the output surface 246. The light exitsoptical extractor 240 through output surfaces 246 and 248. In general,the output surfaces 246 and 248 have optical power, to redirect thelight exiting the optical extractor 240 in angular ranges 239 and 239′,respectively. For example, optical extractor 240 may be configured toemit light upwards (i.e., towards the plane intersecting the LEEs andparallel to the x-y plane), downwards (i.e., away from that plane) orboth upwards and downwards. In general, the direction of light exitingthe luminaire through surfaces 246 and 248 depends on the divergence ofthe light exiting light guide 230 and the orientation of surfaces 242and 244.

Surfaces 242 and 244 may be oriented so that little or no light fromlight guide 230 is output by optical extractor 240 in directions thatare within a certain angle of the forward direction (i.e., in certainangular ranges relative to the positive z-direction). In embodimentswhere the luminaire module 200 is attached to a ceiling so that theforward direction is towards the floor, such configurations can helpavoid glare and an appearance of non-uniform illuminance.

In general, the intensity profile of luminaire module 200 will depend onthe configuration of the optical coupler 220, the light guide 230 andthe optical extractor 240. For instance, the interplay between the shapeof the optical coupler 220, the shape of the redirecting surface 243 ofthe optical extractor 240 and the shapes of the output surfaces 246, 248of the optical extractor 240 can be used to control the angular widthand prevalent direction (orientation) of the illumination.

In some implementations, the orientation of the illumination can beadjusted based on the included angle of the v-shaped groove 241 formedby the portions of the redirecting surface 242 and 244. In this manner,light can be extracted from the luminaire module 200 in a more forwarddirection for the smaller of two included angles formed by the portionsof the redirecting surface 242, 244.

Furthermore, while surfaces 242 and 244 are depicted as planar surfaces,other shapes are also possible. For example, these surfaces can becurved or faceted. Curved redirecting surfaces 242 and 244 can be usedto narrow or widen the beam. Depending on the divergence of the angularrange of the light that is received at the input end 232′ of the opticalextractor 240, concave reflective surfaces 242, 244 can narrow theillumination output by the optical extractor 240, while convexreflective surfaces 242, 244 can widen the illumination output by theoptical extractor 240. As such, suitably configured redirecting surfaces242, 244 may introduce convergence or divergence into the light. Suchsurfaces can have a constant radius of curvature, can be parabolic,hyperbolic, or have some other curvature.

While the luminaire module 200 as described in FIG. 2A includes anoptical extractor 240 with two light output surfaces 246 and 248, aluminaire module can also be configured with one light output surface.FIG. 2B shows an example of luminaire module 200* that is designed tooutput light in the positive x-direction, but not in the negativex-direction. Luminaire module 200* includes substrate 210, LEEs 212(e.g., 4, 6, 10, 20, or more) disposed on substrate 210 that areconfigured to emit light in an emission angular range, and opticalcouplers 220 coupled with corresponding LEEs. Optical couplers 220 arearranged and configured to redirect (or collimate) the light receivedfrom the LEEs into an angular range with a divergence smaller than thedivergence of the emission angular range at least in the x-zcross-section.

Luminaire module 200* also includes a light guide 230 and an opticalextractor 240. The light guide 230 is optically coupled at a light inputsurface with the optical couplers 220 and configured to receive lightfrom the optical couplers 220. Light guide 230 guide the received lightto a light output surface of the light guide 230. The optical extractor240 is coupled with the light output surface of the light guide 230 andconfigured to receive the light that is output by light guide 230.

Optical extractor 240 includes a reflective optical interface 244 and alight exit surface 248. In cross-section, both reflective opticalinterface 244 and light exit surface 248 are convex (as viewed in thedirection of propagation of light) in shape. Light exit surface 248 canhave a constant radius of curvature while the radius of curvature of thereflective optical interface 244 can vary. During operation, opticalcouplers 220 collimate light from LEEs 212 and direct the light to lightguide 230. The light propagates down light guide 230 to opticalextractor 240, and is, at least in part, redirected by the reflectiveoptical interface 244 and is output through the light exit surface 248.A light intensity profile of luminaire module 200*, disposed in aninverted configuration, can be similar to output lobe 165 a shown inFIG. 1B.

Luminaire modules can be used in different orientations, for exampleupright downward, sideways or in other orientations.

FIG. 2C shows an embodiment 200′ of the disclosed luminaire modulearranged in an inverted configuration that is elongated along an axis(e.g., y-axis) perpendicular to the forward direction (e.g., along thez-axis.) In this case, a length L of the light guide 230 along theelongate dimension of the luminaire module 200′ can be 2′, 4′ or 8′, forinstance. A thickness T of the light guide 230 orthogonal to theelongated dimension L (e.g., along the x-axis) is chosen to be afraction of the distance D traveled by the guided light from thereceiving end to the opposing end of the light guide 230. For T=0.05 D,0.1 D or 0.2 D, for instance, light from multiple, point-like LEEs212—distributed along the elongated dimension L—that is edge-coupledinto the light guide 230 at the receiving end can efficiently mix by thetime it propagates to the opposing end.

FIG. 2D shows an embodiment 200″ of the disclosed luminaire modulearranged in an inverted configuration that has a (e.g., continuous ordiscrete) rotational symmetry about the forward direction (e.g.,z-axis.) Here, a diameter T of the light guide 230 is a fraction of thedistance D traveled by the guided light from the receiving end to theopposing end of the light guide 230. For example, the diameter of thelight guide 230 can be T=0.05 D, 0.1 D or 0.2 D, for instance.

Other shapes of the disclosed luminaire module are possible. FIGS. 2Eand 2F show a perspective view and a bottom view, respectively, of anembodiment 200″′ of the disclosed luminaire module (arranged in aninverted configuration) for which the light guide 230 has two opposingside surfaces 230 a, 230 b that form a closed cylinder shell ofthickness T. In the example illustrated in FIGS. 2E and 2F, the x-ycross-section of the cylinder shell formed by the opposing side surfaces230 a, 230 b is oval. In other cases, the x-y cross-section of thecylinder shell can be circular or can have other shapes. Someimplementations of the example luminaire module 200′ may include aspecular reflective coating on the side surface 230 a of the light guide230. Open curved shapes are possible.

Luminaire modules, such as luminaire modules 200, 200*, 290, 200′, 200″,and 200″′ as described above with respect to FIGS. 2A-2F, can beemployed in a luminaire, such as luminaire 100 as described with respectto FIG. 1A. For example, any of the luminaire modules 200, 200*, 290,200′, 200″, and 200′″ can be used to provide light that is, at least inpart, redirected towards target areas I and/or II.

(iii) First Implementation of a Luminaire Including a Luminaire Moduleand Reflectors

FIG. 3A shows an example of a luminaire 300 including a housing 360. Theluminaire 300 further includes a luminaire module 302 and reflectors350′, 350″ disposed within the housing 360.

The housing 360 includes a surface 361 with light output apertures 362′and 362″. The luminaire module 302 (which can be any one of luminairemodules 200, 200*, 290, 200′, 200″, or 200″′) is connected to thesurface 361 of the housing 360 and arranged in an upright position, asdescribed below. The light output apertures 362′ and 362″ are located onopposite sides of an optical axis of the luminaire module 302. In otherimplementations, the outer components of the reflectors 350′ and 350″can be integrally formed or otherwise joined and optionally configuredto provide a housing and replace a separate housing component.

Luminaire module 302 includes LEEs 312 that are configured to emitlight. The luminaire module 302 guides the light emitted by LEEs 312 viaa light guide (along the negative z-axis) and redirects the guided lightusing redirecting surfaces 243 of an optical extractor 340 towards lightoutput surfaces of the optical extractor (with positive z-axispropagation directions), as described above with respect to FIGS. 2A-2F.In some implementations, the redirecting surfaces are configured suchthat a large portion or substantially all (e.g., more than 99% of) thelight that impinges on the redirecting surfaces is redirected towardsthe light output surfaces of the optical extractor (e.g., theredirecting surfaces can include a high reflectance mirror.) The opticalextractor of the luminaire module 302 outputs the redirected lightthrough the light output surfaces of the optical extractor (along thepositive z-axis) into the housing 360 in angular ranges 307′ and 307″.

The housing 360 further includes another surface 365, opposing thesurface 361, such that the optical extractor 340 of the luminaire module302 is adjacent the other surface 365. The other surface 365 of thehousing 360 can be parallel to the surface 361. In some implementations,the housing 360 includes one or more side surfaces 367-a, 367-bextending along the z-axis between the opposing surfaces 361 and 365. Insome implementations, the surfaces 361, 365, 367-a, 367-b of the housing360 are formed from a metal, e.g., sheet metal. Here, circuitry used topower the LEEs 312 of the luminaire module 302 is insulated from themetal of the housing surfaces. In other implementations, the surfaces361, 365, 367-a, 367-b of the housing 360 are formed from an insulatormaterial, e.g., plastic, fiber glass, etc.

Reflectors 350′, 350″ receive the light that is output by the luminairemodule 302 in the angular ranges 307′, 307″ and redirect at least aportion of the light output by the luminaire module 302 towardsapertures 362′ and 362″, respectively. In this example, each ofreflectors 350′, 350″ includes first and second opposing reflectivesurfaces arranged and shaped to reflect components of the light that isoutput by the luminaire module 302 in angular ranges 307′, 307″. Here,the reflected light can bounce between the first and second reflectivesurfaces of each of the reflectors 350′ and 350″ as it propagate in aforward direction or directly reach the respective output aperture 362′,362″. The light received at the light output apertures 362′, 362″ fromthe reflectors 350′, 350″, respectively, passes through the light outputapertures 362′, 362″ and exits the housing 360 of the luminaire 300 withangular ranges 308′ and 308″, respectively.

In some implementations, the light output apertures 362′, 362″ caninclude an optical window 305′, 305″ that is configured to diffuse thereceived light symmetrically or asymmetrically to create a desiredillumination profile.

(iv) Second Implementation of a Luminaire Including a Luminaire Moduleand Reflectors

FIG. 3B shows an example luminaire 300′, which is a modification of theluminaire 300 described above in connection with FIG. 3A. Here, each ofthe reflectors 350′, 350″ includes a first reflective surface arrangedand shaped in combination with the configuration of the opticalextractor 340 to reflect the light that is output by the luminairemodule 302 in the angular ranges 307′, 307″, such that the reflectedlight reaches the apertures 362′ and 362″, respectively, after a singlereflection off of the first reflective surface. In this example, thefirst surface of the reflector 350′ is configured to reflect a componentof the light that is output by the optical extractor 340 of theluminaire module 302 in angular range 307′ that propagates in a lateraldirection towards the left side of the luminaire 300′, e.g., along thenegative x-axis. Also, the first surfaces of reflector 350″ isconfigured to reflect a component of the light output by the opticalextractor 340 in angular range 307″ that propagates in a lateraldirection towards the right side of the luminaire 300′, e.g., along thepositive x-axis.

While the housing 360 of luminaire modules 300, 300′ (illustrated inFIGS. 3A and 3B includes reflectors 350′, 350″, luminaire modules havinga housing without reflectors are also possible.

(v) Third Implementation of a Luminaire Including a Luminaire Module andNo Reflectors

FIG. 3C shows an example of a luminaire 300″, which is a modification ofeither of luminaires 300 or 300′ described above in connection withFIGS. 3A and 3B. As such, luminaire module 300″ does not includereflectors 350′ and 350″ to redirect light towards apertures 362′, 362″.Alternatively, the luminaire 300″ is an implementation of luminaire 100,such that a housing 360 without reflectors includes a luminaire module302 within the housing. In this example, light that is output by theoptical extractor 340 of the luminaire module 302 in angular ranges307′, 307″ propagates in forward directions, e.g., along the positivez-axis.

The apertures 362′, 362″ and optical extractor 340 of the luminairemodule 302 can be configured such that substantially all the light thatis output by the optical extractor exits through the light outputapertures 362′, 362″.

Luminaires 300, 300′, and 300″ can be elongated along the y-axis orrotationally symmetric about the z-axis (e.g., about an optical axis ofthe luminaire module.)

In some implementations, luminaires 300, 300′, and 300″ can be fully orpartially recessed in, or surface mounted on, a ceiling or a wall andilluminate one or more target areas below the ceiling or in front of thewall, or provide grazing illumination thereon when partially protrudingor surface mounted, for example. The surface 361 of the housing 360 canbe within, above, or below a plane of the ceiling/wall. In someimplementations, structures that aid in buoyancy driven convectivecooling can be incorporated into the ceiling/wall and coupled with theluminaire module 302 to dissipate heat generated by the LEEs 312.

The luminaires 300, 300′ and 300″ described herein in connection withFIGS. 3A-3C can provide light in one or more controlled angular ranges308′, 308″ that is mixed along a path length that is at least twice thedistance from the LEEs 312 to the optical extractor 340. The light ismixed when it propagates within the light guide of the luminaire module302 and the mixed light that is output by the optical extractor 340 isfurther mixed within the housing 360 when it propagates from the opticalextractor 340 towards the light output apertures 362′, 362″. In someimplementations, stray light, if any, within a housing can be partiallyrecycled and mixed using a diffuse reflective interior housing surface.

Additionally, the light exiting the luminaires 300, 300′ and 300″ canhave an isotropic spectral composition (i.e., the color of the lightdoes not depend on direction.)

1. A luminaire comprising: a housing having a first face with a firstaperture; one or more luminaire modules arranged within the housing,each module comprising: one or more light-emitting elements (LEEs)disposed on one or more substrates and adapted to emit light in a firstdirection; a light guide comprising an input end and an output end, andside surfaces extending from the input end to the output end, the sidesurfaces being shaped to guide light emitted by the one or more LEEs andreceived at the input end of the light guide in the first direction tothe output end of the light guide and provide guided light at the outputend of the light guide; and an optical extractor optically coupled withthe output end of the light guide and adapted to receive the guidedlight, the optical extractor having a first redirecting surface and afirst output surface, the first redirecting surface of the opticalextractor being adapted to reflect at least a portion of the guidedlight received at the optical extractor towards the first output surfaceand output redirected light from the first output surface of the opticalextractor in a second direction opposing the first direction, whereinlight output by the optical extractor through the first output surfacein the second direction passes through the first aperture into anambient environment as first light output by the luminaire.
 2. Theluminaire of claim 1, wherein the one or more substrates are coupledwith the first face of the housing.
 3. The luminaire of claim 1, whereinthe optical extractor comprises a second redirecting surface and asecond output surface on an opposite side of an optical axis of thelight guide relative to the first output surface, the second redirectingsurface of the optical extractor being adapted to reflect at least aportion of the light received at the optical extractor towards thesecond output surface and output redirected light from the second outputsurface of the optical extractor in the second direction, and the firstface has a second aperture wherein light output by the optical extractorthrough the second output surface in the second direction passes throughthe second aperture into the ambient environment as second light outputby the luminaire.
 4. The luminaire of claim 1, wherein the housingcomprises a second face opposing the first face, such that the opticalextractor is adjacent to the second face.
 5. The luminaire of claim 4,wherein the housing comprises one or more side faces extending from thefirst face to the second face along the first direction.
 6. Theluminaire of claim 1, further comprising a first reflector having afirst reflective surface, the first reflective surface being configuredto reflect at least a portion of light that is output from the firstoutput surface of the optical extractor towards the first aperture inthe second direction as reflected light.
 7. The luminaire of claim 6,wherein the first reflector comprises a second reflective surfaceopposing the first reflective surface.
 8. The luminaire of claim 1,wherein the housing is recessed in a ceiling such that the first face ofthe housing is parallel to the ceiling.
 9. The luminaire of claim 8,wherein the first face is within a plane of the ceiling.
 10. Theluminaire of claim 6, further comprising a second reflector having athird reflective surface, the third reflective surface being configuredto reflect at least a portion of light that is output from the secondoutput surface of the optical extractor towards the second aperture inthe second direction as reflected light.
 11. The luminaire of claim 10,wherein the second reflector comprises a fourth reflective surfaceopposing the third reflective surface.
 12. The luminaire of claim 1,further comprising an optical element disposed in at least a portion ofat least one of the first or second aperture.
 13. The luminaire of claim12, wherein the optical element is configured to diffuse light.
 14. Theluminaire of claim 1, further comprising an optical element disposed inat least a portion of at least one of the first or second aperture, theoptical element being configured to refract light.
 15. The luminaire ofclaim 6, wherein at least a portion of at least one of the first orsecond reflective surface is specular reflective.
 16. The luminaire ofclaim 6, wherein the light guide and at least one of the first or secondreflectors are configured to mix the light emitted by the one or moreLEEs to provide a substantially uniform output light at the firstaperture or at the first and second apertures.
 17. The luminaire ofclaim 16, wherein the output light has an isotropic color distribution.18. The luminaire of claim 16, wherein the output light has a uniformintensity distribution along a direction parallel to the planar sidesurfaces of the light guide.
 19. The luminaire of claim 1, wherein thelight guide comprises a solid transparent material and the side surfacesare configured to guide light via TIR.
 20. The luminaire of claim 1,wherein the light guide is hollow and the side surfaces are reflectorsconfigured to guide light via specular reflection.
 21. The luminaire ofclaim 1, further comprising one or more couplers positioned to receive aportion of the light emitted by corresponding one or more LEEs andadapted to at least partially collimate the received portion of thelight, the one or more couplers being positioned to provide collimatedlight to the input end of the light guide.